Equine Navicular Disease and Corrective Shoeing

what is navicular syndrome/ disease

chronic bilateral progressive degeneration of navicular bone and apparatus

what horses get navicular disease

early middle aged horses

quarter horses!!

what is the function of navicular bone

decrease strain on DDFT as it changes direction to cross coffin joint

decrease work of DDFT to act on P3

Collateral sesamoidean ligament of navicular bone will

attach to P2

helps with medial/ lateral stability

what can cause navicular syndrome

conformation

genetics

chronic poor shoeing

what are clinical signs of navicular syndrome

unilateral or bilateral forelimb lameness

short, choppy stride

land toe first

what will conformation look like in navicular syndrome

long toe, low heel

small feet

contracted heels

what is underrun heel

almost walking on heel, angle is really low

how can you diagnose navicular syndrome

sore over heels to hoof tester

positive to coffin joint hyperextension

blocks to PD nerve

can switch lameness to other side if bilateral

when radiographing the navicular bone, what is important

positioning

may need to pull shoe

clean foot!

pack foot with playdoh to remove air pockets

what is evaluated in lateral radiograph of navicular bone

flexor cortex

medullary cavity

insertion of impar lig on distal NB and navicular suspensory lig on proximal NB

hoof balance

what is evaluated on horizontal DP radiograph

hoof balance

lateral and medial aspect of navicular

what is evaluated on 60-65 degree DP radiograph

insertions of navicular suspensory ligament on lateral and medial navicular bone

distal and proximal borders of navicular bone

shape of navicular

what is the #1 view for navicular bone

palmaroproximal palmarodistal oblique (Navicular syline)

What is evaluated in palmaroproximal palmarodistal oblique radiograph

flexor cortex

medullary cavity

corticomedullary junction

shape of navicular

what is medullary sclerosis

loss of corticomedullary junction

if rads are normal, what else could be involved in caudal heel pain

DDF tendon

impar ligament

suspensory ligament of naivicular bone

collateral ligament of DIP joint

navicular bursa

what is the first step in treating navicular syndrome

shoeing

what are treatment options for navicular syndrome

NSAIDs

corticosteroid injection in coffin joint

osteoclast inhibitors if they have bony lesions

what needs to be done when shoeing horse with navicular syndrome

ease breakover

support palmar structures and raise heel

address coffin bone angle

will navicular syndrome ever heal

no, its progressive

prognosis of navicular syndrome depends on

response to treatment

soft tissue involvement

what is palmar digital neurectomy used for

improve lameness and extend the career

alleviates pain but does NOT cure the problem

what is required for horse to be candidate for palmar digital neurectomy

lameness must significantly improve with PD nerve block

no ossification in DDF tendon

no DJD in coffin joint

no roughening of flexor surface of navicular bone

owner compliance

what are potential complications of palmar digital neurectomy

neuroma formation/ neuritis***** most common

DDF tendon rupture

coffin joint subluxation

reinnervation

what can be done to influence breakover

leave toe handing over shoe, setting shoe back

squaring toe

rockering or rolling toe

what is done to support palmar structures

leave long heel on shoe

reverse shoe

bar shoe

support of the bony column will

transfer forces from hoof wale to sole

when does hoof capsule need to be stabilized

P3 fractures

navicular bone fractures

what can be done to stabilize hoof capsule

rim shoes

clips in strategic places

if there is low or negative palmar angle, what would you do

elevate heel

bring angle up

when would shoeing and trimming by radiographs be indicated

laminitis

navicular syndrome

severe hoof imbalance